1. Field of the Invention
The present invention relates to an improvement in an apparatus for mounting a number of conductive balls by moving a ball reservoir for reserving the conductive balls along the upper face of an array mask and, more particularly, to a conductive ball mounting apparatus which is improved with a main view to improving the positional precision of the conductive balls in the through holes of the array mask.
2. Description of the Related Art
As the conductive ball mounting apparatus for mounting conductive balls after the adhesive material was applied to individual electrodes formed in a predetermined array pattern on the mounting target, there exists in the related art an apparatus for mounting the conductive balls, after sucked, arrayed and adsorbed by the ball mounting head having an array plate, on the individual electrodes on the mounting target, as disclosed in JP-A-2001-358451. However, as the mounting target product such as a wafer becomes larger, the number of solder balls to be mounted at one time exceeds one million. This makes it difficult at present to reduce the defects in the array of solder balls and the defects at the mounting time.
As disclosed in JP-A-2002-538970 and Japanese Patent No. 3177370, therefore, there has been provided an apparatus, in which an electronic substrate or a mounting target printed with flux is provided with an array mask and in which solder balls are directly dropped onto electrodes of the electronic substrate. As compared with the diameter of the conductive balls, however, the diameter of the through holes of the array mask is larger. This raises a problem that the positions of the conductive balls in the through holes are not arranged merely by dropping the conductive balls into the through holes of the array mask.